As in all of the “Game of Life” sub-series of the Shine Cycle, the setting of The Harbor is our solar system in the, now quite far, future: the late twenty-eighth century, about ninety years after the events of The Convergence. The main and point-of-view character is presumably still Alice Hansen, also known as Alatumbra, by now far and away the oldest woman alive, a mage and diplomat no longer officially active as the liaison between the nations of Earth and the interuniversal alliance that has defended Earth in the past.

In the twenty-eighth century, Earth is increasingly marginal in human society in the galaxy. After it resoundingly rebuffed a raid by a fleet from a group of planets whose resource consumption was outstripping their production capacity, its nations fought but badly lost a war to reunify humanity—or even the nearer colonies—under its leadership.

Aside from an edge in some kinds of research, the Solar System’s main point of notability is the presence of a “refit harbor” established by and for the Federation of Allied Navies, a primarily trade-protection alliance associated with the great interuniversal alliance to which several of Earth’s nations have belonged for a few hundred years.

Alice Hansen is officially “liaison emerita” between the nations of Earth and both the great alliance and the FAN, but she has made a point of keeping abreast of everything it would have been her job to know before she passed the formal responsibility on. Soon after our story begins, she finds she is noticing a pattern of unexpected equipment replacement that looks like someone testing in preparation for sabotage.

At first not certain of her suspicions, and having no firm conclusion yet, she investigates a little further, but once she feels she has enough evidence she gathers a team of mages, anaalysts, and others to search for the enemy agent or agents behind the sabotage and try to prevent any further damage.

Alice Hansen and her team find the enemy agents, but they capture and interrogate the lead agent just days too late to be able to stop the sabotage devices that were alread placed from destroying the main refueling station in Earth orbit, which is the largest such station in the system and a major component of the “refit harbor.” In questioning this agent, however, they learn that he or she was sent by Gondolor to damage the system’s defenses in advance of an attack by interstellar missiles.

To try to mitigate the possible damage, she arranges a defense in depth: she sends mages she trained off to each station in the system that is marked for FAN use, sends the most talented pilots she knows throughout the system to try to intercept the missiles, and urges any docked ships to depart. However, the missile bombardment arrives before all is quite ready, and despite heroic efforts by pilots and mages, a “dry-dock” and a shuttle bay are destroyed.

In the aftermath, Alice Hansen gathers a team of engineers, mages, and software developers to develop shielding to forestall future attacks and sensors to detect attempted sabotage, and by leaning slightly on her contacts in the Federation of Allied Navies ensures that every station in the system will have these defenses. Then she returns to what she considers her retirement.